A patient dealing with respiratory illness, for example chronic obstructive pulmonary disease (COPD), can have difficulty engaging in effective respiration. This difficulty may be the result of a variety of physiological faults, including a breakdown of lung tissue, dysfunctions of the small airways, excessive accumulation of sputum, infection, genetic disorders, or cardiac insufficiency. With such illnesses, it is useful to provide the patient with a therapy that can improve the ventilation of the patient. In some situations, the patient can be provided with a respiratory therapy system that includes a gas source, an interface that may be used to transmit gas to an airway of a patient, and a conduit extending between the gas source and the interface. Gas delivered to an airway of the patient from the gas source can help to promote adequate ventilation of the patient. The gas source may, for example, be a container of air and/or another gas suitable for inspiration, for example, oxygen or nitric oxide, a mechanical blower capable of propelling a gas through the conduit to the interface, or some combination of both. The respiratory therapy system may include structure used to heat and/or humidify gases passing through the system to improve patient comfort and/or improve the prognosis of the patient's respiratory illness.
A patient suffering from respiratory conditions may benefit from reducing the volume of air that he inhales that does not take part in the normal gas exchange of oxygen (O2) and carbon dioxide (CO2). This volume of air is contributed to by anatomical dead space, which is gas that includes exhaled CO2 captured in the patient's airways that is rebreathed upon inspiration. To reduce dead space, the patient can be treated with high flow therapy, which can involve the administration of gas to the airways of a patient at a relatively high flow rate and at a relatively low pressure. The high flow of gases reaching the patient's airways can be beneficial for flushing out the patient's airways, which can reduce the volume of anatomical dead space. High flow therapy is often delivered with an unsealed patient interface such as, for example, a nasal cannula.
It is an object of certain embodiments disclosed herein to provide an improved or alternative system and method for respiratory therapy that might overcome or ameliorate problems with existing systems or methods, or at least provide the public with a useful choice.